The pseudoscorpion family Menthidae is reexamined and 4 genera and 8 species are recognised: Menthrus Chamberlin with M. rossi (Chamberlin), M. mexicanus Hoff, M. lindahli (Chamberlin) and M. californicus Chamberlin from south-western USA. and Mexico, Oligomenthus Beier with O. argentinus Beier from Argentina and O. chilensis Vitali-di Castri from Chile, Thenmus Harvey, gen, nov. with T. aigialites Harvey, sp. nov. (type species) from north-eastem Australia, and Paramenthus Beier with P. shulovi Beier from Israel. Adults of all menthid species are found to have 11 trichobothria on the fixed chelal finger and hand. Post-embryonic development is investigated.